It is, of course, quite impossible even today to argue the question of slavery. To many, the offence lies in the mere fact; to others, it lies in the operation of the system. At all events, the institution is no longer tolerated in any civilized country. While some to whom the system itself was a bitter offence have found much to criticize in its operation in Cuba, the general opinion of observers appears to be that it was there notably free from the brutality usually supposed to attend it. The Census Report of 1899, prepared under the auspices of the American authorities, states that "while it was fraught with all the horrors of this nefarious business elsewhere, the laws for the protection of slaves were unusually humane. Almost from the beginning, slaves had a right to purchase their freedom or change their masters, and long before slavery was abolished they could own property and contract marriage. As a result, the proportion of free colored to slaves has always been large." Humboldt, who studied the institution while it was most extensive, states that "the position of the free negroes in Cuba is much better than it is elsewhere, even among those nations which have for ages flattered themselves as being most advanced in civilization." The movement for the abolition of slavery had its beginning in 1815, with the treaty of Vienna, to which Spain was a party. Various acts in the same direction appear in the next fifty years. The Moret law, enacted in 1870 by the Spanish Cortes, provided for gradual abolition in Spain's dominions, and a law of 1880, one of the results of the Ten Years' War, definitely abolished the system. Traces of it remained, however, until about 1887, when it may be regarded as having become extinct forever in Cuba.